The authors investigate the dynamic modelling problem and the active vibration control design problem for a flexible Timoshenko robotic manipulator in this study. For the practical robotic manipulator, the authors analyse the dynamic characteristic considering the shear deformation and elastic deflection of the flexible arm link and describe this flexible system with a coupled partial differential equation and ordinary differential equations (PDE–ODEs) model. Furthermore, the authors design the active vibration control and disturbance observers to solve the vibration problem of the flexible robotic manipulator under the external disturbances, namely, to reduce the shear deformation and the deflection of the flexible Timoshenko link. Besides, the manipulator is driven to track the given angular position with an active angular controller, simultaneously. The effectiveness of the designed vibration control laws is analysed by the theoretical analysis and verified by the numerical simulation.